> There's also a lot of "New" versions of older European locations as a way to distinguish them from other similarly named places when there aren't any rivers nearby, I guess

A whole lot of those “New” places (unsurprisingly, given patterns of human habitation more generally) have rivers nearby.

> There's Manchester-by-the-Sea, MA.

And Cardiff by the Sea, Carmel-by-the-Sea, and Corona del Mar, CA.